drivers/net/phy/mdio-mux-gpio.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2011, 2012 Cavium, Inc.
   7  */
   8
   9 #include <linux/platform_device.h>
  10 #include <linux/device.h>
  11 #include <linux/of_mdio.h>
  12 #include <linux/module.h>
  13 #include <linux/phy.h>
  14 #include <linux/mdio-mux.h>
  15 #include <linux/gpio/consumer.h>
  16
  17 #define DRV_VERSION "1.1"
  18 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
  19
  20 struct mdio_mux_gpio_state {
  21         struct gpio_descs *gpios;
  22         void *mux_handle;
  23 };
  24
  25 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
  26                                    void *data)
  27 {
  28         struct mdio_mux_gpio_state *s = data;
  29         int values[s->gpios->ndescs];
  30         unsigned int n;
  31
  32         if (current_child == desired_child)
  33                 return 0;
  34
  35         for (n = 0; n < s->gpios->ndescs; n++)
  36                 values[n] = (desired_child >> n) & 1;
  37
  38         gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
  39                                        values);
  40
  41         return 0;
  42 }
  43
  44 static int mdio_mux_gpio_probe(struct platform_device *pdev)
  45 {
  46         struct mdio_mux_gpio_state *s;
  47         int r;
  48
  49         s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
  50         if (!s)
  51                 return -ENOMEM;
  52
  53         s->gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
  54         if (IS_ERR(s->gpios))
  55                 return PTR_ERR(s->gpios);
  56
  57         r = mdio_mux_init(&pdev->dev,
  58                           mdio_mux_gpio_switch_fn, &s->mux_handle, s);
  59
  60         if (r != 0) {
  61                 gpiod_put_array(s->gpios);
  62                 return r;
  63         }
  64
  65         pdev->dev.platform_data = s;
  66         return 0;
  67 }
  68
  69 static int mdio_mux_gpio_remove(struct platform_device *pdev)
  70 {
  71         struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
  72         mdio_mux_uninit(s->mux_handle);
  73         gpiod_put_array(s->gpios);
  74         return 0;
  75 }
  76
  77 static const struct of_device_id mdio_mux_gpio_match[] = {
  78         {
  79                 .compatible = "mdio-mux-gpio",
  80         },
  81         {
  82                 /* Legacy compatible property. */
  83                 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
  84         },
  85         {},
  86 };
  87 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
  88
  89 static struct platform_driver mdio_mux_gpio_driver = {
  90         .driver = {
  91                 .name           = "mdio-mux-gpio",
  92                 .of_match_table = mdio_mux_gpio_match,
  93         },
  94         .probe          = mdio_mux_gpio_probe,
  95         .remove         = mdio_mux_gpio_remove,
  96 };
  97
  98 module_platform_driver(mdio_mux_gpio_driver);
  99
 100 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 101 MODULE_VERSION(DRV_VERSION);
 102 MODULE_AUTHOR("David Daney");
 103 MODULE_LICENSE("GPL");